Pulsars slow down their rotation as they age and eventually cease their characteristic emissions. That can change if an aging pulsar is a member of a binary system containing a normal star. Gas flowing from the star can spin the pulsar up to hundreds of revolutions a second and allow it to resume its lighthouse-like beams of radiation. Credit: NASA
Radio searches netted 17 new millisecond pulsars by examining the Fermi Gamma-ray Space Telescope’s list of unidentified sources. Colored circles indicate the positions of the new pulsars on the Fermi one-year all-sky map. Credit: NASA/DOE/Fermi LAT Collaboration
› Larger image Radio astronomers have uncovered 17 millisecond pulsars in our galaxy by studying unknown high-energy sources detected by NASA’s Fermi Gamma-ray Space Telescope. The astronomers made the discovery in less than three months. Such a jump in the pace of locating these hard-to-find objects holds the promise of using them as a kind of “galactic GPS” to detect gravitational waves passing near Earth.
A pulsar is the rapidly spinning and highly magnetized core left behind when a massive star explodes. Because only rotation powers their intense gamma-ray, radio and particle emissions, pulsars gradually slow as they age. But the oldest pulsars spin hundreds of times per second — faster than a kitchen blender. These millisecond pulsars have been spun up and rejuvenated by accreting matter from a companion star.
“Radio astronomers discovered the first millisecond pulsar 28 years ago,” said Paul Ray at the Naval Research Laboratory in Washington. “Locating them with all-sky radio surveys requires immense time and effort, and we’ve only found a total of about 60 in the disk of our galaxy since then. Fermi points us to specific targets. It’s like having a treasure map.”
Millisecond pulsars are nature’s most precise clocks, with long-term, sub-microsecond stability that rivals human-made atomic clocks. Precise monitoring of timing changes in an all-sky array of millisecond pulsars may allow the first direct detection of gravitational waves — a long-sought consequence of Einstein’s relativity theory.
“The Global Positioning System uses time-delay measurements among satellite clocks to determine where you are on Earth,” explained Scott Ransom of the National Radio Astronomy Observatory in Charlottesville, Va. “Similarly, by monitoring timing changes in a constellation of suitable millisecond pulsars spread all over the sky, we may be able to detect the cumulative background of passing gravitational waves.”
The sources Fermi detected are not associated with any known gamma-ray emitting objects and did not show evidence of pulsing behavior. However, scientists considered it likely that many of the unidentified sources would turn out to be pulsars.
For a more detailed look at radio wavelengths, Ray organized the Fermi Pulsar Search Consortium and recruited a handful of radio astronomers with expertise in using five of the world’s largest radio telescopes — the National Radio Astronomy Observatory, Robert C. Byrd Green Bank Telescope in W.Va., the Parkes Observatory in Australia, the Nancay Radio Telescope in France, the Effelsberg Radio Telescope in Germany and the Arecibo Telescope in Puerto Rico.
After studying approximately 100 targets, and with a computationally intensive data analysis still under way, the discoveries have started to pour in.
“Other surveys took a decade to find as many of these pulsars as we have,” said Ransom, who led one of the discovery groups. “Having Fermi tell us where to look is a huge advantage.”
Four of the new objects are “black widow” pulsars, so called because radiation from the recycled pulsar is destroying the companion star that helped spin it up.
“Some of these stars are whittled down to masses equivalent to tens of Jupiters,” said Ray. “We’ve doubled the known number of these systems in the galaxy’s disk, and that will help us better understand how they evolve.”
NASA’s Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership, developed in collaboration with the Department of Energy, along with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden, and the U.S. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
Francis Reddy
Goddard Space Flight Center
BTW We use to think, almost unconciously, that laws are “sacred”, they bear a name of a supposed “saint” who we are to believe in. That is simply prejudice.
We have been taught to believe and accept and self indulge and to unconciously deceive and be deceived and be comforted by agreement and sociallized “consensus”.
If we are to find anything new at all we should start from zero, from not knowing before hand and asking ourselves…what if…?
By irrespecting those “saints” we are suppose to believe in and just ignoring that bunch of laws none ever tested in a lab we’ll be opening new grandiose vistas of the universe we live in, and we must not feel ashamed if what we find anyone can comprehend it because of its natural simplicity.
snowmaneasy (08:50:46) :
Of course this means that “I Love Lucy” has reached Vega
Once we have conquered faster-than-light space travel, we may finally be able to get ahead of and recapture the broadcasts of the “lost” Doctor Who episodes.
Question: Are these quasar signals individually unique enough to identify specific quasars? This may be needed for Galactic GPS to account for Doppler shift variances as we travel around the galaxy, especially if we end up using teleportation and have to figure out where we’ve suddenly appeared.
Silly question, but why use pulsars for gravity wave detection? Why not use the existing EM radiation from distant stars/galaxies instead?
[twinkle, twinkle – – – – – ?]
JonesII (09:56:55) :
laws should be reproducible in the lab
All accepted physical laws we know of have come from and are supported by laboratory evidence.
Quote: Leif Svalgaard (09:42:56) :
quotes: Oliver K. Manuel (09:14:28) :
‘WHY? Many scientists and ordinary citizens believe that neutron stars are dead nuclear embers that remain after a star explodes.
Nothing could be further from the truth.’
“What you said next:
A central neutron star may explain the energy, neutrinos, and Hydrogen pouring from the surface of any “ordinary” star is what is furthest from the truth.”
Leif comprehends little or nothing about nuclear rest mass data for the 3,000 types of atoms that comprise the entire visible universe:
http://www.omatumr.com/Data/2000Data.htm
His model of the Sun is like an innocent child’s model of an apple:
“The outside is red, so the inside must be red, too.”
And he fails to grasp anonymous hints (coincidences) that would lead a child to reconsider his model:
The solar surface is 91% H (element #1), the lightest of all elements.
The solar surface is 9% He (element #2), the next lightest element.
http://www.omatumr.com/images/Fig1.htm
It doesn’t take a rocket scientist, or a HS diploma, to see the obvious.
I believed that fairy tale in 1960, before I started making measurements.
With kind regards,
Oliver K. Manuel
Former NASA PI foer Apollo
http://myprofile.cos.com/manuelo09
*******
John Cooke (06:55:52) :
Too late. We’ve been transmitting our radio then TV signals into space for over 100 years – so they’re now reaching stars up to 100 light years away. If “they” 🙂 can’t detect and locate the origin of our radio and TV signals then their technology isn’t great! Radio waves travel considerably faster than Voyager.
*******
Yeah, but the power of those transmissions is prb’ly too small to be discernable from background radio noise more than a couple light-yrs away from earth.
This is off my head, but I’d bet.
*******
Henry Galt (06:35:58) :
We have sent the location of our species into the void in the form of a pulsar map etched onto plaques fitted to our spacecraft.
*******
Yeah, but the chances of anybody/thing finding such a tiny object in the vastness of interstellar space are negligible. Not that I think advertising ourselves to outside space purposely is a good idea. Read Greg Bear’s sci-fiction The Forge of God and even better Anvil of Stars
Leif Svalgaard (09:36:02) :
JonesII (06:26:02) :
For the sake of clarity: Radio signals are electric signals
No, they are not
I’m afraid my microwave oven does work this way.
Leif Svalgaard (09:36:02) :
JonesII (06:26:02) :
For the sake of clarity: Radio signals are electric signals
No, they are not.
Seems like a matter of semantics to me. Radio “signals” are EM waves, aren’t they? EM waves are carriers of electrical energy ( unless the MIT professor mispoke ).
I am still trying to figure out how a body accreting mass “spins up”, when additional mass, at least in our corner of the universe, seems to “spin” things down? I really don’t think I can read another of those boring astrophysical papers.
sarc off
Henry Galt (06:35:58) :
“We have sent the location of our species into the void in the form of a pulsar map etched onto plaques fitted to our spacecraft.”
A fact I added earlier in the month to the pulsar article on wikipedia – I was surprised it wasn’t already there.
Can we say that radio waves are a frequency on the electromagnetic spectrum just as light, X-rays, infrared, and gamma rays?
So-called “neutronium” is a theoretical substance that has never been observed in the laboratory and neutrons will not stay together and also isolated neutrons breakdown into a proton and a free electron.
The assumption that pulsars “spin” is more based on a lack of other hypothesis rather than empirical evidence.
In reality, “Science doesn’t know” is probably the best answer.
Quote: James F. Evans (14:41:19) :
“So-called “neutronium” is a theoretical substance that has never been observed in the laboratory and neutrons will not stay together and also isolated neutrons breakdown into a proton and a free electron.”
Neutron stars are held together by gravity, but energized neutrons (e.g., ~12 MeV) can and do penetrate this gravitational barrier (e.g., ~90MeV) and escape. Solar wind Hydrogen is the decay product of these neutrons from the solar core.
Just as 4 MeV Helium-4 nuclei (alpha particles) are retained in the nucleus of Uranium-238 but manage to penetrate the Coulomb barrier (~30 MeV) and escape.
The half-life of U-238 is about 4.5 Gyr (4.5 x 10^9 yr). We do not yet know the half-life of the neutron star at the solar core that produces solar luminosity, solar neutrinos, and solar-wind H in the proportions observed.
With kind regards,
Oliver K. Manuel
Former NASA PI for Apollo
beng
V’GER
🙂
and
TheGoodLocust
Friends don’t let friends……
but I just went and had a sneaky peek. Seems many writers have had similar ideas.
I thought about the dumbness of the plaques as, many years ago, I investigated humans whose names are immortalised off-planet.
e.g. “I am not a crook” and “Operation Kozara”.
I think, with due respect for holy science, neutrons are held together by human stubborness. Self sex “marriages” are not a valid natural couple, like the CERN experiment, it won´t create any black holes or discover the hidden nature of God.
JonesII (13:28:20) :
I’m afraid my microwave oven does work this way.
I’m afraid it does not. There are no electric currents in your oven.
LAShaffer (14:29:11) :
EM waves are carriers of electrical energy
No, they carry electromagnetic energy.
But the oldest pulsars spin hundreds of times per second — faster than a kitchen blender.
A good graphic of what one of these objects may look like can be found here
I have to agree with Leif, EM maybe caused by electric currents or electric currents cause EM. EM can pass thru insulators and hard vacuum, electric currents can not.
EM or better EMF (Electro Motive Force) is a general term for all the phenomina.
Electrical energy and currents are in or on a conductor and the carriers are electrons.
As to the discriptsion of a millisecond pulsar, this defies logic. I think we need a new theory. Sometimes starting over with all the new known data is better then patching up the old theory.
Let’s try that again.
But the oldest pulsars spin hundreds of times per second — faster than a kitchen blender.
here
PG: logic and reality are seen as unnecessary constraints by the theoreticians that dream these things up.
Jeremy:
I don’t believe in Neutron Stars, because they are such a ridiculous idea. They fail even a basic reality check as PG observes. Then on top of that they involve the invention of a new state of matter which is not directly observable (and they call this science). Basically as an engineer I don’t trust mathematicians that much.
In the case of pulsars, the same effect can demonstrably be obtained with no moving parts. So why go to all the trouble of inventing neutron stars. What we are observing is analogous to a high energy electrical spike reflecting up and down a power transmission line.
I think that the electrical theory of pulsars makes certain predictions. In particular all pulsars will be found to consist of a binary system.
In the meantime the existing theory serves the same valuable purpose as the barriers around a hole in the road. Whenever anyone mentions a neutron star you can steer well clear. Same goes for black holes, imho, fine as an idea for sci-fi movies, but not vaguely realistic.
isn’t the best
p.g.sharrow “PG” (22:26:30) :
“EM or better EMF (Electro Motive Force) is a general term for all the phenomina (sic).”
EM (or em) is an abbreviation for electromagnetic as in emr (electromagnetic radiation), emi (electromagnetic induction) or emc (electromagnetic compliance). EMF (or emf) electromagnetic force is a different animal, and is certainly not “a general term for all the phenomina (sic)”. Specifically, electromotive force is the difference in electric potential (or less formally ‘Voltage’) and is measured in Volts. (1 Volt = 1 Joule / Coulomb).
Sorry. ’emf electromagnetic’ should read ’emf electromotive’.
Oliver K. Manuel (15:03:47)
Dr. Manuel’s above comment is partially in response to this quote:
“So-called “neutronium” is a theoretical substance that has never been observed in the laboratory…”
The long and short of Dr. Manuel’s comment is this:
“Yes, it’s true that “neutronium” has never been observed in the laboratory — but that doesn’t matter, my theories depend on its existence, and so that’s my story and I’m sticking to it…”
That’s not good science Dr. Manuel…with all due respect.
Quote: James F. Evans (07:48:17) :
“So-called “neutronium” is a theoretical substance that has never been observed in the laboratory…” etc.
“That’s not good science Dr. Manuel…with all due respect.”
Sorry, James, but I did not claim the existence of “neutronium”.
Whether or not you like it,
a.) Gravity is a nuclear force; the nucleus contains essentially all mass.
b.) There is a repulsive force between neutrons; therefore no black holes.
Dynamic competition between long-range attractive gravitational forces and and short range repulsive forces between neutrons powers the Sun and cosmos and fills interstellar space with hydrogen – a neutron decay-product that pours from the Sun’s surface in the solar wind.
Each year the Sun releases 50,000 billion metric ton of hydrogen in the solar wind.
With kind regards,
Oliver K. Manuel
http://www.omatumr.com/index.html